hello everyone I create a cluster in postgres-XL but I use the command pg_ctl promote but I need a standby server how I can create it I need the cluster to be high availability
You can't do this. Postgres-XL does not support HA or any fail over protection. If you lose a single node the entire database is lost.
The best option they provide is to have a mirror instance of each node, but even with this if a node fails you will still have to manually take the database down and removed the failed node and replace it with its mirror.